The study, which was conducted in the United Kingdom and followed nearly 750 bees at 26 sites, found that a major source for the bumblebee decline in recent years stemmed from "the spillover of parasites and pathogens and disease" from managed honeybee hives, the Associated Press reported.

"There is some reason for concern here," study coauthor Matthias Fuerst of the Royal Holloway University of London told the Agence France-Presse.

"Honeybees and bumblebees have very similar levels of those pathogens at the same site, so that means there is some connection between honeybees and bumblebees at those sites that is highly indicative of a spillover," Fuerst explained.

According to Fuerst, the same pathogen responsible for killing off honeybees when found on a bumblebee resulted in a 25 to 33 percent reduction of their typical 21-day lifespan.

Of the honeybees tested at the study's 26 sites, 88 percent were found to be infected with the pathogens, according to researchers, who warned however that the numbers could actually be significantly higher.

"We’re only catching individuals that are alive and healthy and able to go out and forage," principal author Mark J.F. Brown told the Los Angeles Times. "It’s likely that the prevalence numbers that we report are lower than they actually are."

Much like honeybees, bumblebees play a vital role in pollinizing flowers and food around the world, particularly tomatoes, according to experts.